Perianal Paget’s Disease and Malignancies of Lower Hindgut and Anal Canal

Perianal Paget’s disease (PPD) consists of a skin neoplasia whichcan be either primary or secondary to an underlying internal malignancy.Treatment of perianal Paget’s disease associated with primarycolonic or anal adenocarcinoma is secondary to the treatment of theprimary tumor and, thus, accurate clinical, pathological and immunohistochemicalassessment is essential. Adenocarcinomas are estimatedto be only 10% of anal cancer, and anal mucinous or colloidadenocarcinoma is an even rarer entity. We reviewed literature concerningthe association between malignancies of the lower gastrointestinaltract and anal canal not associated with a chronic fistula-inanoand perianal Paget’s disease, focusing on immunohystochemicaldifferential diagnosis and management. Immunohistochemistryis very useful in choosing the ideal treatment for perianal Paget’s disease; our “immunopanel” is useful to classify perianal Paget’sdisease.